Thermostat switch and plug construction



May 31, 1932. H. L. ELLIS 1,860,999

THERMOSTAT SWITCH AND PLUG CONSTRUCTION Filed July 17, 1930 iff/359%; aY? 770 IN V EN TQR.

Patented May 3l, 1932 UNITED STATES PATENT oFFlcE HERBERT L ELLIS, OFNEW YORK, N. Y., .LSSIGNOR TO EMIL 3R13, 0F NEW YORK, N. Y. THERMOSTATSWITCH AND PLUG CONSTRUCTION Application nl'ed July 17,

My invention relates to thermostat controlled switches.

The object of my invention is to provide a thermostat switch and plugcombination suitable for use with electrically heated flatirons-etc.that may be easily and cheaply constructed. One object is to provide aconstruction that may be removed from the casing, or quickly assembledtherein. A further object is to rovide a thermostat construction thatmay ge adjusted to operate the switch at a given degree of temperatureto break the circuit controlled thereby, and to cool the thermostat asquickly as the iron cools, to cause the switch to again act to restorethe circuit thru the heating coil of the iron. L

The particular features of novelty are shown in the drawings which forma part of this specification, in which Fig. 1 is a View of the plug as1t appears in full size for use with a flat iron.

Fig. 2 is a central sectional vertical view of the plug, shown on anenlarged scale.

Fig. 3 is a cross sectional view on line 3 3 of Fig. 1. A

F-ig. 4 is a cross sectional view on line L1?-4 of Fig. 1. l o

Fig. 5 is a cross sectional view on Ime 5-5 of Fig. 1`.

10 indicates the body portion of the plug casing, which is preferablymade of plastic insulating material, and 11 indicates the cover portionof the casing.`

The casing is provided with achamber 12 and a slot 13 extendingtherefrom into chamber 14. The chamber 14 is entirely separated from themain chamber 15 and from the chamber 12. Located in the body portion,but not attached thereto in any way, is a socket 16 formed to fit over aterminal post 20 carried by the fiat-iron, and a iiat sheet metal stri13 is connected to the socket 16 by a screw 1 The metal strip 13 -isprovided with an 1930. Serial No. 468,505.

oifset fiat portion 18 at each end, thru which screws 17 and 19 extendto connect the socket 16 and electrical conductor 22 respectively.

The thickness of the strip 13 is equal to the width of the slot 13, andthe upper end of the strip is oiset and rests in a pocket 23 ing whichit fits closely to prevent movement of the strip, but from which it maybe removed, since there is no mechanical connection between the stripand body ortion.

The inner walll 15 of the cham r 15 prevents heat from the irontransmitted to the strip 13 and socket 16 from being radiated to thethermostat 24 located in the chamber 15 and thereby permits thethermostat to cool more quickly after the circuit is broken, than itotherwise would.

A socket 25 is adapted to fit over a terminal post 21 carried by theflat-iron, and has an extending portion 25 having a length about equalto that of the len h of the socket, said extending portion eingconnected to a bracket 26 by a screw 27 as illustrated.

The thermostat 24 is connected to the bracket 26 and extends downward incontact with the casing of the socket extension 25 and socket casing 25the entire length of both, so that heat transmitted from the iron willflow from the post 21 into the socket casing and quickly into thebi-metallic metal thermostat, and may cool quickly due to the coolingair which may flow thru the holes 28 and 29 formed in the casing 10. Thehole 28 extends the full width of the chamber 15. The thermostatI 24 isbent into the form shown, and its free upper end carries a metal contactpiece 30 and a piece of non-conducting material 31, such as bakelite,both of said pleces being secured together and to the end of thethermostat by a single screw 32 which extends thru a hole in thethermostat and piece 30, and screws into the non-conducting material 31.i

An indent 30 is formed in the upper side of the piece 30 and a similarindent 31 is formed in the upper side of the piece 31, these indentsbeing spaced from each other a predetermined distance within themovement of the thermostat. A thin casting 33 is formed as shown, andsecured to the body of the casing by clamping it between the body andcover at 34 and a screw 35 extends thru its upper end and secures oneend of the conductor 36 thereto. rl`he lower end of the casing 33 isformed to provide a housing 37 open at its under side, the inner wallsof which serve as a guide for a cylindrical contact member 38 having aflat top, and a ball or cone shaped.

lower end adapted to rest in the indents 30 and 31 respectively.

A helical spring 40 rests on the top of the member 38 and is compressedto the required degree in adjusting the timing action of the switch', bya thumb-screw 41 which screws thru the top of the housing 37. The edge41 of the thumb-screw extends thru slots 42 respectively, formed in thecasing 10 and cover 11, and are exposed to view, and are graduated toaid in setting the screw to time the action of the thermostat. It willbe noted that the edge 41 extends substantially even with the outersurface or plane of the plug, and thus permits of easy manipulation.

The casing is also provided with an opening 43 at its upper end, and anannular groove 44 is formed in its surface to receive a collar 45 whichis attached to the lead-in wires 22 and 36, to relieve them of strain,as will be readily understood.

The cover is secured to the body portion by screws 46 which extend thrushort tubes 47 interposed between the cover and body portion as shown.

The device operates as follows:

The switch operates by heat conducted from the heater in the iron, tothe thermostat.

Assuming the sockets 16 and 25 to be attached to the terminal posts 20and 21, as illustrated in Fig. 2, said {iat-iron having an electricheater therein, and the thermostat 24 to have expanded and operated theswitch to open the electric circuit, as shown in the drawings. Cool airflowing thru the openings 28 and 29 into the chamber 15, will cause thethermostat to cool as the iron cools, to a predetermined degree, whenthe thermostat will actuate the switch to close the circuit, (which isits normal condition) and current will flow to the heater in the iron asfollows:

Electric current flows in thru the conductor 22, strip 17 and socket 16to terminal post 20 which is in circuit with the heater in the iron, andfrom the heater to the terminal post 21, and thence thru the socket 25,and its extension 25 to the thermostat 24 and metal contact piece 30,and thence thru the cylindrical contact piece 38 and casting 33 to thereturn conductor 36, leading to the source of power. The timing of theaction of theswitch is regulated by the thumb-screw 41 which controlsthe pressure of the spring 40 on the member 38 as will be readilyunderstood. It will be observed that the extreme movement of the switchin bothdirections, is limited by the inner walls of the chamber 15.

The circuit is interrupted by a snap action obtained by the resiliencyof the thermostat in the usual manner.

Having thus described my invention, I claim as new:

1. A thermostat switch and plug construction comprisinga body portionand a cover therefor, a thermostat switch located in said body portioncomprising a thermostat having a metal block and anon-conductor carriedon its free end by a rod which extends thru the metal and into thenon-conductor, said metal block and non-conductor each having a detenttherein, a housing, a metal contact member adapted to engage saiddetents to retard the action of the switch, means for timing the actionof the switch and means for clamping said mechanism in said body portionin removable relation thereto.

2. As stated in claim 1 said timing means comprising a thumb screw whichextends thru the casing and is limited in its vertical movement in bothdirections by the adjacent walls thereof.

3. A thermostat switch and plug construction comprising a body portionhaving a plurality of chambers formed therein and having a laterallyextending socket at each side thereof formed to receive and embrace theend of a bare flat conductor, two conductors each having one end formedto fit in said sockets respectively and held in position by the sidewall thereof, a housing connected with one of said conductors and astrip conductor with the other, a thermostat and switch mecha` nismlocated in one of said chambers, and means comprising a cover forclamping said mechanism in said body portion.

4. A thermostat switch and plug construction comprising a body portionhaving a chamber formed therein, a socket having an extension thereon, athermostat connected to said extension and extending in contacttherewith the entire length thereof, said thermostat formed with a loopand having a contact member on its free end; a contact member adapted tocontact the member carried by the thermostat and close a circuittherethru, a second socket, electrical conductors in circuit with saidsockets, and means comprising a cover for clamping said conductors andmetal parts in said body portion.

5. A thermostat switch and plug construction comprising a body portionhaving a main chamber formed therein, a chamber formed in the upper endthereof and a chamber formed between said chamber, a thumb screw locatedin said last named chamber the ioo edge of which extends thru the outerwall of the body portion, and limited in its movement by the inner upperand lower wall of said chamber, a thermostat and switch located in saidmain chamber, a housing, a Contact member in said housing, a Contactmember Carried by said thermostat to Contact with said member in thehousing, electrical conductors for said switch members, a cover, and omeans for clamping said switch mechanism in said body in freelyremovable relation when said cover is removed.

In testimony whereof I, HERBERT L. ELLIS affix my signature. HERBERT L..ELLIS.

